The Earth’s Tides

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What effect does the moon have on Earth?

• Tides-• rise and fall of water levels due to gravitational forces

• Occur twice a day (2 high tides, 2 low tides)

http://home.hiwaay.net/~krcool/Astro/moon/moontides/

high tide

low tide

How are Tides created?

• (3 ways)1. Because the Earth and

the moon are attracted to each other

http://home.hiwaay.net/~krcool/Astro/moon/moontides/

Moon and earth are attracted to each other by gravity

Tides are also created by:

•2. the rotation of the earth, •3. and the sun’s gravity

The sun can raise the tides, too

Spring Tides

Tides are not waves!

What are Spring tides?

• Tides that produce the greatest difference between high and low tides—The biggest tides

• Occur twice a month

When do spring tides occur?

• Once at the full moon and once at the new moon

• When the sun moon and earth are nearly in a line

Spring Tides combined with big storms

The sun can raise the tides, too

Spring Tides –the sun

and the moon line up

What are NEAP Tides?

• Tides that produce the least difference between high and low tides—The smallest tides• Occur twice a

month

When do neap tides occur?

• Once at the first quarter and once at the third quarter

• When the sun moon and earth are at right angles to each other

http://www.space.gc.ca/asc/eng/educators/resources/astronomy/multimedia/module3/tides/tides.swf

The neap tides –the smallest tides –when the sun and moon are at a 90 angle

•What other effects do we have from the moon??